I would like you to tell me what do you think about my design, I will try to describe as exhaustly as I can all the decisions taken.

Loudspeaker system

These are a 3 way loudspeakers.

Tweeters (2 by cabinet) mounted in panel, in both front and rear directions. The one which points to the back of the loudspeaker is designed for make the high frequency sound less directivity through the reflexiones of the waves with the walls of the room. Connected in parallel and out of phase ( as Linkwitz did )

Woofers mounted in panel, also to get less directional sound .

Subwoofers(2 by cabinet) mounted in push pull configuration. Connected in parallel and out of phase.

Simulations:

64liters box for the subwoofers. Acceptable cone displacement. fs= 40Hz ( I will correct electronically the SPL so I will be able to play music till 20Hz). Simulations pictures are taken for 100 l internal box, but results doesnt change so much... Simulations

Mechanical

I will use 3/4 inches ( 19mm ) DMF wood for building the cabinets. Each cabinet will weight about 30 or 40 kg ( without drivers!! )

External sizes of the cabinet 400mmx400mmx1250mm.

I will use 1/2 inches ( 12mm) DMF wood for internal structure to give the structure mechanical resistance.

Also tweeter mounting ... it depends on the project and it may give that extra 'sizzle'
or it might do nothing .

The idea of keeping the woofer free is good - free means not interfering with the natural
movement of the cone by putting boundaries near it- but I would still control the back emission , by putting some stuffing / sound absorber behind it.

Most people don't have any clue of how music has to be reproduced, so I wouldn't spend money just to verify if a Java app works in reality ...
In most cases the magic rule is : keep it simple -which is already a big problem !

If you are going to experiment in dipole diffusion- I guess that's the goal of the design-
you may mount everything...well,not everything, just the two subwoofers- on a baffle .
The rest , I'd follow Stig Erik's way of suspending them with rubber bands .

If the goal is to see what the rear facing tweeter does, take a simple well known conventional small box speaker with an electronic crossover and switching to add in or kill a rear tweeter. When experimenting, change one thing at a time. You have described a very complex project. Another approach would be to use a pair of full range speakers, electronic crossovers and eq, see what effect different corners and eq have on the imaging.

You may not want to hear it, but the secret to fantastic imaging is not more drivers, it is room treatments.